Orifice introducer device

ABSTRACT

An orifice introducer device for introducing, e.g., a surgical device, into, e.g., an orifice of a body, includes a tubular member having a distal end and a proximal end. The distal end is adjustable between a first position for insertion into an orifice and a second position once inserted into the orifice. Alternatively, the orifice introducer device includes a distal portion having a proximal end configured to be detachably secured to the distal end of the tubular member. The distal portion is selectively detachable when the orifice introducer device is positioned in the orifice.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application claiming the benefit of and priority to U.S. application Ser. No. 10/632,271, filed on Jul. 31, 2003, which claims the benefit of and priority under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/400,023, filed on Jul. 31, 2002, the entire contents of each of which being expressly incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an orifice introducer device, and more particularly, to an orifice introducer device for introducing, e.g., a surgical device, into an orifice of a body.

BACKGROUND

There are many surgical procedures that require a surgical instrument to be introduced into an orifice of a body. One example of such is a surgical procedure to resect a cancerous or anomalous tissue from a gastro-intestinal tract by the introduction, e.g., insertion, of a circular stapling instrument via a patient's oral or anal cavity.

One of the problems experienced during surgical procedures of this type is that the orifice of the body may be damaged when the surgical instrument is being introduced, or has been introduced, into the orifice. This is particularly problematic when the orifice into which the surgical device is being introduced includes fragile tissue that is easily damaged when contacted, e.g., the tissues of the oral cavity. Another problem experienced during surgical procedures of this type is that the surgical instrument may be damaged when the surgical instrument is being introduced, or has been introduced, into the orifice. It may be particularly important to avoid damage to the surgical device, since a patient may also be harmed if the surgical device functions improperly.

While significant advances have been made in miniaturizing surgical instruments, there are still many surgical instruments that are almost as large as, the same size as, or larger than, the size of the orifice into which the surgical instrument is required to be introduced. Since the likelihood of damaging either the orifice or the surgical device may be increased as the size of the surgical device increases relative to the size of the orifice into which the surgical instrument is required to be introduced, conventional surgical devices and procedures still risk damage to one or both of the surgical device and the orifice.

Thus, there is a need for a device that minimizes the likelihood of damage to one or both of a surgical device and an orifice when the surgical device is introduced into the orifice.

SUMMARY

The present invention, according to various embodiments thereof, relates to an orifice introducer device for introducing, e.g., a surgical device, into, e.g., an orifice of a body. The orifice introducer device includes a tubular member having a distal end and a proximal end. The distal end is adjustable between a first position for insertion into an orifice and a second position once inserted into the orifice. Alternatively, the orifice introducer device may include a distal portion having a proximal end configured to be detachably secured to the distal end of the tubular member. The distal portion is selectively detachable when the orifice introducer device is positioned in the orifice.

In another example embodiment of the present invention, the introducer includes a tubular sheath. The diameter of the proximal end of the sheath is larger than the diameter of the distal end of the sheath. For example, the sheath may have a generally conically-shaped or tapered distal end. The diameter of the distal end may be expandable to allow passage of a surgical instrument whose diameter is larger than the diameter of the distal end. The distal end may include, for example, a slit, seam or weakened area for allowing the diameter to expand. Alternatively or additionally, the distal end may be formed of a stretchable material, such as an elastomeric material, which allows the diameter of the proximal end to expand.

In another example embodiment of the present invention, the introducer includes a sheath and a distal cap-like portion (e.g., a nose cone). The distal cap-like portion may be removably mounted to the sheath. The cap-like portion may be removed from the sheath and withdrawn or recovered through the sheath.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view that illustrates an orifice introducer device in a closed position, according to one example embodiment of the present invention;

FIG. 1B is a side view that illustrates, in an open position, the orifice introducer device illustrated in FIG. 1A;

FIG. 2A is a perspective view that illustrates an orifice introducer device according to another example embodiment of the present invention.

FIG. 2B is a partial perspective view that illustrates further details of a proximal end of the orifice introducer device illustrated in FIG. 2A;

FIG. 2C is a partial side view that illustrates further details of a distal end of the orifice introducer device illustrated in FIG. 2A in a closed position;

FIG. 2D is a side view that illustrates further details of the distal end of the orifice introducer device illustrated in FIG. 2A in an open position;

FIG. 3A is a side view that illustrates an orifice introducer device according to another example embodiment of the present invention;

FIG. 3B is a partial, cross-sectional side view of the orifice introducer device illustrated in FIG. 3A;

FIG. 3C is a partial, cross-sectional side view that illustrates further details of an attached distal portion of the orifice introducer device illustrated in FIG. 3A;

FIG. 3D is a partial, cross-sectional side view that illustrates further details of a detached distal portion of the orifice introducer device illustrated in FIG. 3A;

FIG. 3E is a partial, cross-sectional side view of the orifice introducer device illustrated in FIG. 3A having a second tubular body inserted therein;

FIG. 3F is a partial, cross-sectional side view of the orifice introducer device illustrated in FIG. 3A having the second tubular body further inserted therein;

FIG. 3G is a partial, cross-sectional side view of the orifice introducer device illustrated in FIG. 3A having distal portion partially withdrawn therethrough; and

FIG. 3H is a partial, cross-section side view of the orifice introducer device illustrated in FIG. 3A having distal portion partially withdrawn through the second tubular body.

DETAILED DESCRIPTION

The present invention, according to various embodiments thereof, relates to an orifice introducer device that may be used, for example, for introducing or inserting, e.g., a surgical device, into an orifice, e.g., an oral cavity, of a body. For the purposes of example only, the present invention will be described hereinafter in connection with an orifice introducer device that is used for introducing or inserting a surgical device into an orifice of a body. However, it should be recognized that the present invention, in accordance with other embodiments thereof, may also be used for introducing or inserting anything, e.g., a surgeon's hand, an implantable medical device, etc., into an orifice of a body. Additionally or alternatively, it should be recognized that the present invention, in accordance with other embodiments thereof, may also be used for widening or otherwise changing the shape of an orifice of a body for purposes other than introducing or inserting something into the orifice of a body, e.g., for enabling a surgeon to view externally the interior of the orifice without introducing or inserting anything therein. Still further, it should be recognized that the present invention, in accordance with other embodiments thereof, may also be used for introducing or inserting an element into any type of orifice, not merely an orifice of a body.

Advantageously, the orifice introducer device of the present invention may function to prevent damage to either the orifice of the body or to the surgical instrument when the surgical instrument is being introduced or inserted, or has been introduced or inserted, into the orifice. Additionally or alternatively, the orifice introducer device may function so that a surgical instrument having a relatively large diameter may pass through an orifice having a relatively smaller diameter without damaging the orifice. Preferably, the orifice introducer device has a first position or arrangement in which the orifice introducer device is configured to be easily inserted into an orifice. In addition, the orifice introducer device is adjustable to a second position or arrangement in which the orifice introducer device may accommodate, e.g., a larger surgical instrument therethrough, by, for example, maintaining, stretching or otherwise changing the shape of, an orifice so that the larger surgical device may be inserted and positioned therein. Preferably, the orifice introducer device is configured to be sterilizable, enabling it to be used more than once.

FIGS. 1A and 1B illustrate, in a first position and a second position, respectively, an orifice introducer device 100 suitable for introducing a surgical device into an orifice of a body, in accordance with an example embodiment of the present invention. In this embodiment, the orifice introducer device 100 includes a generally tubular member 1. The tubular member 1 has a proximal end 1 a and a distal end 1 b. A diameter of the distal end 1 b is, in the first position, smaller than the diameter of the proximal end 1 a. In this embodiment, the distal end 1 b is generally conical or tapered in the first position. In addition, the distal end 1 b includes, in the embodiment shown, a longitudinal slit 2.

FIG. 1B illustrates the adjustability of the distal end 1 b. More specifically, FIG. 1B illustrates that, in the second position, the distal end 1 b is adjusted such that an diameter of the distal end 1 b is increased, e.g., expanded, relative to the diameter of the distal end 1 b in the first position. For instance, the inner diameter of the distal end 1 b is expanded to allow a surgical device, for example a surgical device having a diameter that is larger than the diameter of the distal end 1 b in the first position, to pass therethrough. In this embodiment, the distal end 1 b is adjustable by the opening of the longitudinal slit 2.

In operation, the distal end 1 b of the tubular member 1 is introduced into an orifice and is advanced in a distal direction until it achieves a desired position within the orifice. The relatively smaller diameter at the distal end 1 b permits the orifice introducer device 100 to be more easily introduced and advanced into the orifice. Preferably, when the orifice introducer device 100 is positioned in the desired position, the proximal end 1 a of the tubular member 1 remains outside of the orifice. A surgical instrument, which may be sterilizable, may then be inserted into the tubular member 1 and may be advanced distally therethrough. The surgical instrument may include, for example, a surgical instrument attached to a flexible shaft of an electromechanical driver, as described in, for example, U.S. Pat. No. 6,443,973, entitled “Electromechanical Driver Device For Use With Anastomosing, Stapling, and Resecting Instruments,” filed on Jun. 2, 1999, U.S. patent application Ser. No. 09/510,927, entitled “An Electromechanical Driver And Remote Surgical Instruments Attachments Having Computer Assisted Control Capabilities, filed on Feb. 22, 2000, U.S. Pat. No. 6,517,565 entitled “Carriage Assembly for Controlling a Steering Wire Steering Mechanism Within a Flexible Shaft”, filed on Feb. 22, 2000, U.S. Pat. No. 6,315,184, entitled “Stapling Device For Use With An Electromechanical Driver Device For User With Anastomosing, Stapling, And Resecting Instruments,” U.S. Pat. No. 6,264,087, entitled “Parallel Jaw Device For Use With An Electromechanical Driver Device,” U.S. Pat. No. 6,348,061, entitled “Vessel And Lumen Expander Attachment For Use With An Electromechanical Driver Device,” U.S. Pat. No. 6,488,197, entitled “Fluid Delivery Device For Use With Anastomosing, Resecting and Stapling Instruments, filed on Feb. 22, 2000, U.S. Pat. No. 6,491,201, entitled “A Fluid Delivery Mechanism For Use With Anastomosing, Resecting And Stapling Instruments, filed on Feb. 22, 2000, U.S. Pat. No. 6,533,157, entitled “A Tissue Stapling Attachment For Use With An Electromechanical Driver Device, filed on Feb. 22, 2000, U.S. patent application Ser. No. 09/887,789, entitled “Electro-Mechanical Surgical Device,” filed on Jun. 22, 2001, U.S. patent application Ser. No. 10/098,217, entitled “Trocar Device,” filed on Mar. 14, 2002, U.S. patent application Ser. No. 10/128,768, entitled “Bipolar Or Ultrasonic Surgical Device, filed on Apr. 22, 2002, U.S. patent application Ser. No. 10/127,310, entitled “Imaging Device,” filed on Apr. 22, 2002, U.S. Patent Application Ser. No. 60/352,726, entitled “Surgical Imaging Device,” filed on Jan. 30, 2002, U.S. patent application Ser. No. 09/999,546, entitled “Surgical Device,” filed on Nov. 30, 2001, U.S. patent application Ser. No. 10/094,051, entitled “A Surgical Device,” filed on Mar. 8, 2002, and U.S. Patent Application Ser. No. 60/388,644, entitled “Surgical Device,” filed on Jun. 14, 2002, each of which is expressly incorporated by reference in its entirety.

When the surgical instrument reaches the distal end 1 b of the tubular member 1, the diameter of the distal end 1 b may be adjusted, e.g., expanded, so as to permit at least a. portion of the surgical instrument to enter, e.g., to extend through, the distal end 1 b. The expansion of the distal end 1 b may be caused by, for example, the force of the surgical instrument pushing against the inner wall of the tubular member 1. In the example shown in FIGS. 1A and 1B, the distal end 1 b expands via the longitudinal slit 2, e.g., by the separation of the sides 2 a and 2 b of the slit 2, to allow the surgical instrument to pass therethrough.

While the embodiment of FIGS. 1A to 1B illustrates that the distal end 1 b of the tubular member 1 may be adjustable, e.g., expandable, alternative arrangements are possible in which the entire tubular member 1 is adjustable. Furthermore, while the embodiment of FIGS. 1A to 1B illustrates that the distal end 1 b of the tubular member 1 may be adjustable, e.g., expandable, via a slit 2, alternative arrangements for providing adjustability to the distal end 1 b are also possible. For example, the distal end 1 b of the tubular member 1 may be formed of a stretchable material, such as an elastomeric material, whereby the force of the surgical instrument, e.g., a surgical instrument having a diameter that is larger than the diameter of the distal end 1 b in a first position, against the inner wall of the tubular member 1 may stretch the material of the distal end 1 b to allow the diameter of the distal end 1 b to increase and the surgical instrument to pass therethrough. Alternatively or additionally, the distal end 1 b of the tubular member 1 may include one or more seams, perforations, or weakened areas that tear, split or otherwise open or stretch to allow the inner diameter of the distal end 1 b of the tubular member 1 to increase.

FIGS. 2A to 2D illustrate an orifice introducer device 200 in accordance with another example embodiment of the present invention. In this embodiment, and as illustrated in FIG. 2A, the orifice introducer device 200 includes a tubular member 21 having a proximal end 21 a and a distal end 21 b. The distal end 21 b of the tubular member 21 includes a longitudinally extending v-shaped opening or slit 21 e, with a distal end of the opening 21 e being wider in the open position than a proximal end of the opening 21 e. In this embodiment, each of the sides 21 c, 21 d of the opening 21 e includes a number of holes 22 through which a string 22 a may be laced, threaded or corsetted. The proximal end 21 a of the tubular member 21 includes an actuation device 20. The actuation device 20 may include a ring 25 or the like for gripping the string 22 a.

As shown in further detail in FIG. 2B, the ring 25 may include a hole 25 a through which both ends of the string 22 a pass. Specifically, the first and second ends of the string 22 a are laced within the holes 22 at the distal end 21 b of the orifice introducer device 100, extend through the interior of the tubular member 21 and emerge through holes 23 and 27 a, respectively. The first and second ends of the string 22 a are secured to the ring 25 through the hole 25 a by a crimp 26. As shown, the hole 27 a may include a grommet 27 to, for example, reduce the friction of the string 22 a against the sides of the hole 27 a.

Prior to insertion of the orifice introducer device 200 into an orifice, the ring 25 may be moved, e.g., pulled in a proximal direction, to draw the sides 21 c and 21 d of the opening 21 e together and thereby reduce the diameter of the distal end 21 b of the tubular member 21 as illustrated in FIG. 2C. The reduced diameter of the distal end 21 b of the tubular member 21 permits easier insertion of the orifice introducer device 200 into an orifice. After the orifice introducer device 200 has been inserted into an orifice and is in a desired position, the diameter of the distal end 21 b of the tubular member 21 may be increased as illustrated in FIG. 2D to allow a surgical instrument to be passed therethrough. In order to increase the diameter of the distal end 21 b of the tubular member 21, the ring 25 may be moved in an opposite direction, e.g., in a distal direction, thereby releasing the tension on string 22 a.

It should be recognized that there are numerous different arrangements that may be employed for lacing the string 22 a through the holes 22 at the distal end 21 b of the tubular member 21 and for securing the string 22 a to an actuation device 20, such as the ring 25, at the proximal end 21 a of the tubular member 21. For instance, in another example embodiment of the present invention, the crimp 26 may be secured to the tubular member 21 at a proximal side of the hole 27 a. The first and second ends of the string 22 a may extend through the hole 25 a of the ring 25 to be connected to the crimp 26. The ring 25 may then be moved in one direction, e.g., distally, to decrease the diameter of the distal end 21 b of the tubular member 21 and in an opposite direction, e.g., proximally, to increase the diameter of the distal end 21 b of the tubular member 21.

FIGS. 3A to 3G illustrate an orifice introducer device 400, and the use thereof, according to another example embodiment of the present invention. In this embodiment, a generally tubular member 300 is provided with a distal portion 310, e.g., a nose cone, at a distal end 315 thereof. The tubular member 300 may be formed from, for example, a Teflon material. The distal portion 310 is configured to be detachably mounted to the distal end 315 of the tubular member 300. The distal portion 310 may be generally conically shaped or tapered so that a distal end of distal portion 310 has a smaller diameter than a proximal end of the distal portion 310 and the tubular member 300. The distal portion 310 is generally sized and shaped to be inserted into an orifice. The distal portion 310 may have an open or closed distal end, and may be, for example, tapered, conical, frusto-conical, blunt, etc., in shape. The proximal end 325 of the distal portion 310 may be generally annularly shaped so as to be attachable to the distal end 315 of the tubular member 300. In this embodiment, the distal portion 310 may be at least partially formed from a flexible, e.g., elastomeric, material. The distal portion 310 may be, for example, stretched around the distal end 315 of the tubular member 300. Additionally or alternatively, other methods and/or devices can be used to attach the distal portion 310 to the distal end 315 of the tubular member 300, including by way of non-limiting example: an electrical connection, an adhesive, a tacky composition, a coupling member, a fastener, a material which molecularly binds with the material of the tubular member, etc.

FIG. 3B is a partial cross-sectional view of the orifice introducer device 400 illustrated in FIG. 3A. As shown in FIG. 3B, the proximal end 325 of the distal portion 310 includes an annular groove 320. The annular groove 320 is configured to receive the distal end 315 of the tubular member 300. FIG. 3C shows further details of a portion of the annular groove 320. As shown in FIG. 3C, the annular groove 320 is configured to frictionally retain between opposing members 320 a and 320 b the distal end 315 of the tubular member 300.

As noted above, in this embodiment, the distal portion 310 may be formed from a flexible, e.g., elastomeric, material. FIG. 3D illustrates the portion of the annular groove 320 shown in FIG. 3C, when the distal end 315 of the tubular member 300 is not inserted therein. As shown in FIG. 3D, the proximal end 325 of the distal portion 310 in which the annular groove 320 is housed is biased so as to bend inwardly, e.g., to have a reduced diameter, when the distal end 315 of the tubular member 300 is not inserted in the annular groove 320. Preferably, the proximal end 325 of the distal portion 310 is sufficiently biased such that, when the distal end 315 of the tubular member 300 is not inserted in the annular groove 320, the inwardly-bent proximal end 325 of the distal portion 310 has an outer diameter that is less than an inner diameter of the tubular member 300.

FIGS. 3E to 3G illustrate the use of the orifice introducer device 300 shown in FIGS. 3A to 3D, according to one example embodiment of the present invention. In this embodiment, the orifice introducer device 400 is used with a tubular insertion device 330. For instance, FIG. 3E illustrates the orifice introducer device 400 having a tubular insertion device 330 inserted therethrough. In one embodiment, the tubular insertion device 330 is formed from a Teflon material. The tubular insertion device 330 is slidably receivable in the tubular member 300 and is configured to contact an inner wall 311 of the distal portion 310. Preferably, the tubular insertion device 330 has a sufficient length such that, when fully inserted through the tubular member 300, a proximal end 330 a of the tubular insertion device 330 extends beyond a proximal end 300 a of the tubular member 300 permitting manipulation of the tubular insertion device 330 by a surgeon outside the orifice.

The orifice introducer device of FIG. 3E further includes a recovery device such as a string 340 securely attached to the inner wall 311 of the distal portion 310. Preferably, a proximal end 340 a of the string 340 extends beyond the proximal end of the tubular member 300 so that the string 340 can be held and/or pulled by a surgeon in a proximal direction while the tubular member 300 is left in position within the orifice.

In operation, the distal portion 310 is detachably mounted on the tubular member 300 via, e.g., the annular groove 320. The tubular member 300, including the distal portion 310 is then introduced into the orifice. Once the tubular member 300 is properly position, the tubular insertion device 330 is inserted into the tubular member 300. Alternatively, the tubular insertion device 330 may be inserted into the tubular member 300 prior to introduction and/or positioning of the tubular member 300 in the orifice. The tubular insertion device 330 is then advanced within the tubular member 300 in a distal direction, until the distal end of the tubular insertion device 330 contacts the inner wall 311 of the distal portion 310. The tubular insertion device 330 is then further distally advanced so as to cause the distal portion 310 to be detached from the proximal end 300 a of the tubular member 300. Alternatively, the tubular member 300 may be pulled back proximally, while the tubular insertion device 330 is kept in place. FIG. 3F shows, for example, the distal portion 310 after it is detached from the tubular member 300.

Once the distal portion 310 is detached from the distal end 315 of the tubular member 300, the proximal end 310 a of the distal portion 310 may contract. Advantageously, the proximal end 310 a of the distal portion 310 contracts sufficiently such that the outer diameter of the distal portion 310 is smaller than the inside diameter of the tubular member 300. The tubular insertion device 330 then may be removed from the tubular member 300 by moving it proximally relative to the tubular member 300. Moreover, since upon contraction the outer diameter of the distal portion 310 is smaller than the inside diameter of the tubular member, the distal portion 310 may be withdrawn through the tubular member 300 by pulling the string 340 proximally. Thereafter, the tubular member 300 remains in position within the orifice, and a surgical device may be inserted into the proximal end of the tubular member 300 and advanced distally therethrough.

As seen in FIGS. 3E-3G, in use, as discussed above, the distal portion 310 is movable between a first expanded configuration when the distal portion 310 is attached to the distal end of the tubular member 300 and a second contracted configuration when the distal portion 310 is detached from the distal end of the tubular member 300. As seen in FIG. 3E, in the first expanded configuration the proximal end 310 a of the distal portion 310 is oriented towards a proximal direction, and as seen in FIGS. 3F-3H, in the second contracted configuration the proximal end 310 a of the distal portion 310 is oriented towards a distal direction.

Alternatively, as seen in FIG. 3H, in one example embodiment of the present invention, the proximal end 310 a of the distal portion 310 contracts sufficiently such that the outer diameter of the distal portion 310 is smaller than the inside diameter of the tubular insertion device 330, such that the distal portion 310 may be proximally withdrawn through the tubular insertion device 330 while leaving the tubular insertion device 330 in place within the tubular member 300. In this embodiment, both the tubular member 300 and the tubular insertion device 330 may remain in position within the orifice, and a surgical device may thereafter be inserted into the proximal end 330 a of the tubular insertion device 330 and advanced distally therethrough.

Several embodiments of the present invention are specifically illustrated and/or described herein. However, it will be appreciated that modifications and variations of the present invention are covered by the above teachings without departing from the spirit and intended scope of the present invention. 

1. An orifice introducer, comprising: a tubular sheath having a proximal end and a distal end, a diameter of the distal end of the sheath being expandable from a first diameter to a second diameter to allow passage of a surgical instrument having a diameter that is larger than the first diameter, wherein the distal end of the sheath includes at least one of a slit, a seam, a perforation and a weakened area, which allows the expansion of the distal end.
 2. The orifice introducer of claim 1, wherein the distal end of the sheath is conically shaped at least when the diameter of the sheath is the first diameter.
 3. The orifice introducer of claim 1, wherein the distal end of the sheath is tapered at least when the diameter of the sheath is the first diameter.
 4. The orifice introducer of claim 1, wherein the distal end of the sheath is formed of a stretchable material so that the distal end of the sheath stretches to expand from the first diameter to the second diameter.
 5. An orifice introducer device, comprising: a tubular member having a distal end and a proximal end; the distal end being adjustable between a first position for insertion into an orifice and a second position once inserted into the orifice, wherein, in the first position, the distal end has a smaller diameter than the proximal end, and wherein the diameter of the distal end is greater in the second position relative to the first position.
 6. The orifice introducer device of claim 5, wherein at least a portion of the distal end is stretchable, and wherein the diameter of the distal end is adjusted to the second position relative to the first position by stretching.
 7. The orifice introducer device of claim 5, wherein the distal end includes a slit, and wherein the diameter of the distal end is adjusted to the second position relative to the first position by opening of the slit.
 8. The orifice introducer device of claim 7, wherein the distal end includes a plurality of holes adjacent to the slit and a string threaded through the holes, and wherein the opening of the slit is controlled by a movement of the string.
 9. The orifice introducer device of claim 8, wherein at least one end of the string is attached to an actuation device for controlling a movement of the string.
 10. The orifice introducer device of claim 9, wherein the actuation device includes a ring attached to the string.
 11. A method for using an orifice introducer device comprising the steps of: providing a tubular member having a distal end and a proximal end, the distal end being in a first position in which the distal end has a smaller diameter than the proximal end; inserting the distal end of the tubular member into a body orifice; and adjusting the distal end of the tubular member into a second position.
 12. The method of claim 11, further comprising the step of: inserting a surgical device through the tubular member.
 13. The method of claim 11, wherein the adjusting step includes adjusting a diameter of the distal end of the tubular member so as to have a greater diameter in the second position relative to the diameter in the first position.
 14. The method of claim 11, wherein the adjusting step includes stretching at least a portion of the distal end of the tubular member.
 15. The method of claim 11, wherein the adjusting step includes opening a slit in the distal end of the tubular member.
 16. The method of claim 15, wherein the opening of the slit includes the step of moving, via an actuation device, a string attached to the slit. 